1. Field of the Invention
The present invention relates generally to a recording and/or reproducing apparatus and, more particularly, to a tape medium recording and/or reproducing apparatus for recording or reproducing images, voices, or other data on or from information tracks obliquely formed on a tape medium.
2. Description of the Prior Art
In a tape medium recording and/or reproducing apparatus for recording or reproducing information such as, for example, images, voices, or other data on or from information tracks obliquely formed on a tape medium, editing is occasionally performed to rewrite a portion of recorded information. For example, in applications where each of the oblique tracks are divided into several regions, and voices and images are recorded on different regions, it is likely that only the voices or the images are desired to be rewritten or other voices or images are desired to be added thereto (this operation is hereinafter referred to as insert editing). In that case, the recording timing has hitherto been determined based on a detected rotational phase of a cylinder. However, the track recording position on the tape varies according to apparatus. When the insert editing is performed by loading the tape in an apparatus different from the apparatus used for recording, there is a good chance that the recording would be performed on a position different from a target position. If the recording position is inaccurate, the recording is performed on a region other than the region which is desired to be rewritten, and hence, the erroneously recorded region can no longer be reproduced.
U.S. patent application Ser. No. 07/865,584, filed on Apr. 9, 1992, discloses a technique of accurately maintaining the recording position during insert editing by making use of a positioning signal recorded on the tape. According to this disclosure, the positioning signal is recorded on a track at a specific location thereof ahead of the region which is desired to be rewritten. During the insert editing, the positioning signal is initially detected, and the recording timing is subsequently determined based on the detected timing, thereby accurately determining the target position on the track in a direction longitudinally thereof. In addition, a pilot signal, which is generally used for tracking control, is recorded on the region on which the positioning signal is recorded. Accordingly, the recording and/or reproducing apparatus can obtain tracking control information by sampling the level of the pilot signal at a timing determined by the positioning signal. Based on this information, tracking control is performed to thereby accurately determine the recording position in a direction widthwise of the track.
However, in this kind of conventional tape medium recording and/or reproducing apparatus, if the head runs off the track during scanning, e.g., if the tracking position deviates in the course of a head pulling-in or aligning process, which is generally carried out at an initial stage of a tracking control operation to align and locate the head to an edge of a target track, or due to external disturbance such as, for example, load variations during a movement of the tape, the positioning signal cannot be detected as a result of a reduction in the level of a reproduced signal. In this case, the problem arises that the recording timing cannot be determined, and also, another problem arises that no tracking error can be detected. Under such conditions, because the tracking cannot be controlled in a correct direction, neither pulling-in nor restoring operation is carried out during the tracking control.